Field of the Disclosure
The present disclosure relates to a tool changer that replaces a tool attached to a spindle of a machine tool with a next tool positioned at a standby position.
Background of the Disclosure
Examples of conventional tool changers are disclosed in Japanese Unexamined Utility Model Application Publication H04-028931 and Japanese Unexamined Patent Application Publication No. 2000-193062. Both of these tool changers include a tool change arm having tool holding portions at both ends thereof, a support shaft provided in parallel to the spindle of the machine tool for supporting the tool change arm, a rotation mechanism including a rotation drive motor and rotating the tool change arm about an axis of the support shaft by rotational power of the rotation drive motor, and a forward/backward movement mechanism including a forward/backward movement drive motor and a ball screw and moving the tool change arm forward and backward along the support shaft by the ball screw driven by the forward/backward movement drive motor.
According to such a tool changer, a tool attached to the spindle is replaced with a next tool positioned at a standby position by carrying out the following tool change operations in sequence:                1) rotating the tool change arm about the axis of the support shaft by the rotation drive motor and causing one of the tool holding portions of the tool change arm to hold the tool attached to the spindle and the other of the tool holding portions to hold the next tool positioned at the standby position;        2) driving the ball screw by the forward/backward movement drive motor to move the tool changer arm along the support shaft and pull the tool out of the spindle;        3) rotating the tool change arm 180 degrees about the axis of the support shaft by the rotation drive motor;        4) driving the ball screw by the forward/backward movement drive motor to move the tool change arm backward along the support shaft and attach the next tool to the spindle; and        5) rotating the tool change arm about the axis of the support shaft by the rotation drive motor to return the tool change arm to an original position.        